KAUAI, Hawaii - NASA says it successfully flew an inflatable ring that might help land space payloads safely on Mars Saturday despite the failure of a mammoth parachute to fully deploy in the final, bonus stage of the test flight. The test vehicle is called the Low-Density Supersonic Decelerator (LDSD).

"It's a wrap! LDSD vehicle drop and supersonic flight successful!" NASA tweeted at 4:38 p.m. CDT, and the space agency later confirmed it had recovered the test article in the Pacific Ocean. NASA scientists will brief reporters on the test Sunday.

The device is a possible way to solve a tough riddle about slowing big payloads in the thin Martian atmosphere enough to land safely. The Mars Curiosity Rover was landed with an elaborate skycrane, but the rover was much smaller and lighter than the payloads NASA will have to pre-position on Mars to support human landings.

In the test, the LDSD was carried to 120,000 feet above the Earth by a balloon. It was released, and a rocket lifted the vehicle to 180,000 feet. At that point, when it was flying at 4 times the speed of sound, a donut-shaped tube called the Supersonic Inflatable Aerodynamic Decelerator (SIAD) deployed as planned to cut the descent speed roughly in half. It was at this point that the huge parachute was to deploy bringing the test vehicle slowly to earth. It did not deploy as planned, but it did deploy.

The official test phase was launching the vehicle and flying it at supersonic speed to the test altitute. NASA has two more separate launches to formally test the inflatable and the parachute.